Shadowed Lavapit

{t}: Add {b}{r} to your mana pool.
{b}{r}, {t}: Create a 0/10 Rakdos Lavafall creature token with Defender.
{b}{r}{x}: Shadowed Lavapit becomes a X/X Elemental creature with haste and flying. It's still a land. Sacrifice it unless it attacks every turn. If it is sacrificed this way, it deals X damage to target opponent.